A ring beam optics is developed for a circular seam welding of the automotive using a fiber laser, and the polymer material with a circular seam are firmly welded in a super-short time. As the results, with increase of focal length of collimating lens, the outside diameter of the ring laser beam is hardly changed; the inside diameter of the ring laser beam decreases; the width of the ring laser beam is increased in the experiment. Distance (L12) between the first axi-cone lens and the second axi-cone lens increases, the outside diameter and inside diameter as the ring laser beam increases simultaneously, and the width of the ring laser beam is almost fixed. Moreover, it is confirmed that the intensity distribution of the ring beam becomes uniform by adjusting the coaxial performance of collimating lens, the first axi-cone lens and the second axi-cone lens. The ring laser beam has been outside diameter of 54 mm, inside diameter of 47 mm, and width of 3.5 mm, performing the high speed welding of lap joints in the (2+1) mm thickness of polymer material. When pressure is 100 N, laser power is 800 W and irradiation time is 0.6 s, the tensile-shear strength of the polymer material joint with laser welding is approaching to the base metal, whose fracture of the stretching pieces is appeared in the base mental (TPV-elastomer).